We are the international group of theoretical physicists assembled in Stockholm to work on the paradoxes of black holes, hawking radiation, and the deep mysteries of the Universe. Ask us anything!

We're here at the Nordic Institute for Theoretical Physics (NORDITA) ready to take your questions.

We spent this past week working on some of the most challenging questions in theoretical physics. Last Tuesday, our colleague Stephen Hawking presented to us his latest idea to solve the growing paradoxes of black hole physics. We discussed this, and many other ideas, that may light the path towards a deeper understanding of black holes... and perhaps even point us towards the holy grail of physics. The so-called, "Theory of Everything"!

Could black hole Hawking Radiation be a "super-translation" of in-falling matter? Why does the Universe conserve information? Is "information" a physical object or just an idea? Do collapsing black holes bounce and become a super slow-motion white holes? Can black holes have an infinite amount of charge on their surfaces? Or, could black holes not exist and really be “GravaStars” in disguise? We’re trying to find out! Ask us anything!

Special thanks to conference organizers Nordita, UNC-Chapel Hill, The University of Stockholm, and facilitation by KTH Royal Institute of Technology.

Katie Freese
Director of The Nordic Institute of Theoretical Physics
George Eugene Uhlenbeck Professor of Physics at University of Michigan
Founder of the theory of “Natural Inflation."
Author of first scientific paper on Dark Stars.
Author of “The Cosmic Cocktail: Three Parts Dark Matter.”

Ulf Danielsson
Professor of Physics
Uppsala University
Leading expert of String Cosmology
Recipient of the Göran Gustafsson Prize
Recipient of the Thuréus Prize

Yen Chin Ong
Theoretical Physicist
Nordita Fellow

Celine Weimer
Physicist
The Un-firewalled
Queen of the Quark-Gluon Plasma, the CMB Anisotropies, and of the First Baryons
Queen of Neutrinos
Khaleesi of the Great Universal Wave Function
Breaker of Entanglement
Mother of Dragons
KTH Royal Institute of Technology

Gravity explains how heavenly bodies, such as stars and planets, hold together, while quantum mechanics explains what are the properties of ordinary matter. We are trying to understand how these two theories can work together when stars become very compact and collapse to form a black hole. So far, our understanding suggests that black holes should not remain black, but should eventually evaporate. This leaves us with a puzzle about how information of what formed the black hole can still be preserved after the end of the evaporation. That is the puzzling problem we have been discussing all week.

One of the ideas presented that I quite enjoyed was Carlo and Francesca's theory that when a star collapses, it does not form a black hole. It actually 'bounces' over a VEEEEEERRRRYY long period of time (we're talking 10 followed by 50 zeroes or higher, depending on the mass of the initial star. It's a very speculative theory, and based primarily on ideas found in "Loop Quantum Gravity" which is also speculative) However, I found this idea compelling because it challenges us to consider the possibility that the Universe is playing a trick on us! What we think is one thing, may actually turn out to be another in disguise.

Another excellent talk argued that Black Holes are actually "GravaStars" -- in essence, an EXTREMELY dense star.
(I may also be biased because Emil's math was entirely classical and I didn't have to pretend to understand it ;))

Ah, yes. It can be quite hard sometimes because some of the most beautiful ideas in cutting physics are difficult to explain in less than 20 minutes.

I tried once to explain the Anti-De Sitter Conformal Field Theory Duality ("Ads/CFT") to my Mother's kindergarten class. I think one of them got it, but she may been just been eagerly staring at the cookie jar.

What's so pleasurable about attending conferences like these, is that Physicists use the same neurological tools as laymen to try to understand the mysteries of the Universe... our brains are very good at understanding concepts related to motion, so Physicists often discuss new ideas by describing how imaginary particles, or mathematical objects, or even calculations themselves, "move" in an abstract space. For example, its useful to think about equations "going to infinity" rather than resulting in infinity.

So, the layperson uses the same regions in their brain to understand complex processes, they just don't have the massive lexicon of terms and concepts that these cats do.

So, when I've only got 2 minutes to explain"Ads/CFT" on TV, I always try to think about what's literally moving in that space, and how to visualize it.